Hi Nikunj,
Nikunj Mehta wrote:
...
Some systems deal with multiple children types as well. CMIS shows a
good number of such examples where a single folder entry can have
children of four different kinds - policies, relationships, documents,
and descendants [1]. In another example, a Netflix title entry can have
children of 7 different kinds - awards, directors, cast, screen formats,
episodes, seasons, languages [2]. Each different kind leads to its own
feed/collection.
Understood.
Many systems deal with this by putting all children into the same
container, and just distinguish by MIME type. Or my assigning subfolders.
So does this require multiple *different* children feeds?
- Systems that do not support hierarchical names, or which do support
multiple containment, will need an explicit way to find the parents of
a resource (otherwise the implicit containment based on the path names
is sufficient).
No assumption can be made regarding namespaces in AtomPub as that is
managed by the server. A client cannot be constructing new URLs using
formulaic techniques.
Indeed. I just wanted to clarify that this is the main difference from a
filesystem's (or WebDAV's) containment model.
If you are interested in read-write access, then additional requirements
are:
1. How do you discover the collection from a feed?
2. Some collections accept only "entries that represent a collection",
some disallow such entries, and yet others don't place any such
restrictions.
3. What is the meaning of DELETEing an "entry that represents a
collection", especially when its entries may be hard-linked in to other
such entries?
...
DELETE as specified in HTTP/1.1 (RFC 2616) really leaves this open.
WebDAV (RFC 4918) defines a specific hierarchical containment model, but
still leaves this to the server. WebDAV BIND
(<http://greenbytes.de/tech/webdav/draft-ietf-webdav-bind-23.html>)
introduces the necessary terminology for this, and clarifies that
DELETEing something from a collection will not affect other paths to the
resource (as long as these are really distinct paths).
BR, Julian
